Synthesis and io n transport characterization of hot-pressed solid polymer electrolyte (SPE) membranes:(1 - x) poly (ethylene oxide) (PEO):x NaHCO3, where 0 < x < 50 wt.%, have been reported. SPE films have been synthesized using a hot-press technique in place of the traditional solution-cast method. A conductivity enhancement of the two orders of magnitude was achieved in SPE film:70PEO:30NaHCO(3) and this composition has been referred to as optimum conducting composition (OCC). Materials characterization was done with the help of XRD, SEM, FTIR, DSC and TGA techniques. The ion transport behavior in SPE membranes has been discussed on the basis of experimental measurements on their ionic conductivity (sigma), ionic mobility (mu) and some other important parameters. A solid-state polymer battery was fabricated using SPE OCC at room temperature, as a device application.